1. Field of the Invention
The present invention relates to a three-dimensional map display system that displays a three-dimensional map in a bird's eye view.
2. Description of the Related Art
An electronic map displayed on the screen of, for example, a navigation system or a computer may be a three-dimensional map that expresses features such as buildings three-dimensionally. The three-dimensional map is generally displayed by three-dimensionally drawing three-dimensional models by, for example, perspective projection. The three-dimensional map drawn in the bird's eye view by looking down from the upper viewpoint position is capable of displaying a wide area with perspective and thereby has high availability.
The three-dimensional map advantageously enables the user to intuitively understand the geography. Improvement in reality is desired to utilize this advantage. From this point of view, it has been attempted to give perspective to features in the three-dimensional map. For example, Japanese Patent Laid-Open Application No. JP 2006-126445A discloses a technique of specifying the position of the sun shade a three-dimensional model.